Extracorporeal shockwave therapy raises mechanical nociceptive threshold in horses with thoracolumbar pain

Abstract

Summary Background Although extracorporeal shockwave therapy (ESWT) is a common treatment for horses with back pain, effects on mechanical nociceptive threshold (MNT) and multifidus muscle cross sectional area (CSA) in the spine are unknown. Objectives To evaluate effects of ESWT on spinal MNT and multifidus muscle CSA in horses with thoracolumbar pain. Study design Non‐randomised trial. Methods Thoracolumbar spines of 12 horses with thoracolumbar pain were radiographed to document existing pathology. Each horse received three ESWT treatments, 2 weeks apart (days 0, 14, 28). Palpation scores were documented (days 0, 45 and 65). Ultrasonographic CSA of left and right multifidus muscles was recorded at T12, T14, T16, T18, L3 and L5 (days 0, 45 and 65). MNT was measured at the same spinal sites every 7 days (day 0–56). Results Mechanical nociceptive threshold in 10/12 horses (83%) was greater at each time point compared with day 0 (P < 0.05). Mechanical nociceptive threshold increased at all time points at six sites in 2/12 (16%), at five sites in 3/12 (25%), at four sites in 4/12 (33%) and at one site in 1/12 (8%; P < 0.05). Mechanical nociceptive threshold average per cent increase from day 0 to 56 was 64% for the thoracic region (T12–T18) and 29% for the lumbar region (L3–L5). There was no statistical difference in MNT from day 35 to 56 (P = 0.25). A bimodal analgesic trend was observed following ESWT. Degree of radiographic change was not associated with response to treatment. No significant change in multifidus muscle CSA was observed. Main limitations Small study size and lack of control group. Conclusions Three treatments of ESWT 2 weeks apart raised MNT over a 56‐day period in horses with back pain, but did not influence change in CSA of the multifidus muscle. While ESWT appears justifiable for analgesia, physiotherapeutic techniques may be necessary in conjunction for concurrent muscle rehabilitation.

Long‐term outcome and effect of diagnostic analgesia in horses undergoing interspinous ligament desmotomy for overriding dorsal spinous processes

“…However, this finding is in line with ours' as well as others' clinical impression that there is tremendous individual variability on palpation of the thoracolumbar region. Mechanical nociceptive threshold of the dorsum additionally has no relationship with radiographic evidence of either ORDSP or pathology of the thoracic articular facets, as previously discussed . Pain on palpation of the dorsum may therefore not be a sensitive diagnostic for identification of pain directly attributable to thoracolumbar pathology; this underscores the necessity of diagnostic analgesia in combination with other diagnostics for accurate diagnosis of clinically relevant ORDSP …”

“…Mechanical nociceptive threshold of the dorsum additionally has no relationship with radiographic evidence of either ORDSP or pathology of the thoracic articular facets, as previously discussed. 31 Pain on palpation of the dorsum may therefore not be a sensitive diagnostic for identification of pain directly attributable to thoracolumbar pathology; this underscores the necessity of diagnostic analgesia in combination with other diagnostics for accurate diagnosis of clinically relevant ORDSP. 8,19 For the purposes of the study reported here, successful long-term outcome was defined as improvement in clinical signs described prior to surgical intervention rather than return to work at a similar or higher level.…”

“…Hind limb lameness can result in alterations in thoracolumbar dynamics, potentially resulting in clinical signs such as pain on palpation of the dorsum, which may be confused with pain attributable to ORDSP . In addition, it was been recently demonstrated that there is no relationship between mechanical nociceptive threshold response of the dorsum and radiographic grades of ORDSP, indicating that palpation is an insensitive measure of this pathology . Thus, horses without confirmation of clinically relevant ORDSP with diagnostic analgesia may be suffering from other causes of poor performance and are less likely to have clinical improvement with ISLD.…”

Accelerometric Changes before and after Capacitive Resistive Electric Transfer Therapy in Horses with Thoracolumbar Pain Compared to a SHAM Procedure

“…Thoracolumbar pain and associated neuromuscular dysfunction are common clinical entities in the athletic horse [1][2][3]. A great variety of specific disorders may cause thoracolumbar pain in horses, and affect several anatomical structures in the area, i.e., bones, muscles, joints and ligaments, although the most common disorders are the impingement of the dorsal spinous processes and osteoarthritis of the articular facets [4][5][6]. Regardless of the source/s of back pain, some authors have described the pathophysiological pattern of back pain in horses by extrapolating the knowledge and consequences of low back pain in human beings.…”

Evidence‐based medicine

“…It was recommended that such neuromodulation ‘.... be considered for the management of trigeminal‐mediated headshaking in horses ......’. In the second example, back pain in 12 horses was treated with extracorporeal shockwave therapy; the effect on pain was evaluated using the change in mechanical nociceptive threshold. All horses were treated and there was no control group.…”